The present application claims priority to Japanese patent application of Sakane et alt., filed May 23, 2001, No. 2001-153847, and Japanese patent application of Tanase et al., filed Aug. 3, 2001, No. 2001-235974, the entirety of each is hereby incorporated into the present application by this reference.
1. Field of the Invention
The present invention relates to a head protecting airbag device provided with an airbag which is so folded and housed on the upper edge side of a side window as to cover a side window positioned on the side face of a vehicle when the airbag is extending and expanding.
2. Description of Related Art
A head protecting airbag device of the prior art has an airbag which is so folded and housed on the upper edge side of a side window positioned on the side face of a vehicle as to cover the side window when the airbag is extending and expanding (as referred to Unexamined Published Japanese Patent Application No. 2000-272460).
Moreover, the airbag is constructed to cover the side window when the airbag is extending and expanding and to apply a longitudinal tension to the airbag when the airbag is extending and expanding. Specifically, the front side leading end of the airbag is mounted on the front pillar portion of the vehicle body. And, the rear side leading end of the airbag is mounted on the upper edge side of the side window on the vehicle side face and backward apart from the portion of the airbag covering the side window to the lower side.
In the airbag described in the Japanese Patent Application, the longitudinal tension is so developed when the airbag is extending and expanding as to join the portions mounted on the vehicle body at the front side leading end and the rear side leading end.
Here, the reason why the longitudinal tension is developed in the airbag is to suppress the movement of the airbag to the exterior side even if the airbag receives a pushing force to the exterior side.
In case the vehicle having the airbag device mounted thereon is a single-cab vehicle such as a motor truck or a double-cab vehicle, however, the side of the side window toward the rear is a rear wall portion such as a rear panel perpendicularly intersecting the side window.
In this vehicle, moreover, the portion of the airbag covering the side window as far as the lower side is so close to the rear wall portion that there is no space for mounting the rear side end of the airbag. As a result, it is hard to mount the airbag on a vehicle such as the single-cab vehicle which develops the longitudinal tension upon completion of the extension and expansion.
As another head protecting airbag device of the prior art, there is a construction which is disclosed in Unexamined Published Japanese Patent Application No. 9-249089.
This head protecting airbag device comprises guide means for guiding the end portion of the airbag downward when the airbag is extending and expanding which is folded and housed on the upper edge side of the window. This guide means is arranged along the center pillar portion to guide the rear end portion of the airbag downward along the center pillar portion.
However, the head protecting airbag device thus constructed has a disadvantage when it is applied to the airbag which develops the longitudinal tension on the lower edge side upon completion of the extension and expansion. If the tension occurs in advance on the lower edge side of the airbag, the lower edge of the airbag does not smoothly move downward along the guide means and thus the airbag expands insufficiently.
A first object of the invention is to provide a head protecting airbag device which can develop a longitudinal tension easily in an airbag having completed its extension and expansion, even when it is mounted on a vehicle such as a single-cab vehicle having a rear wall portion arranged to intersect a side window generally perpendicularly on the side of the side window toward the rear to be covered with the airbag.
A second object of the invention is to provide a head protecting airbag device, in which an airbag can complete its extension while being smoothly guided by guide means even if the airbag is constructed to develop a longitudinal tension on the lower edge side upon completion of the extension and expansion.
The first object of the invention can be achieved by a head protecting airbag device to be mounted on a vehicle including: a side window positioned on the side face of the vehicle; a rear wall portion arranged on the side of the side window toward the rear; and a pillar portion arranged on the side of the side window toward the front, wherein the rear wall portion is arranged to intersect the side window generally perpendicularly, and wherein the pillar portion is arranged to extend generally vertically, comprising:
an airbag folded and housed on the upper edge of the side window on the interior side so that it can cover the side window when extending and expanding,
wherein the airbag is mounted at its two longitudinal ends on the vehicle body so that it may develop a longitudinal tension when the airbag is extending and expanding,
wherein the airbag is mounted at its front end on the pillar portion, and
wherein the airbag is mounted at its rear end at a position of the rear wall portion removed from the vehicle side face; and
guide means arranged near the corner portion between the rear wall portion and the vehicle side face so as to guide the downward protrusion of the airbag when the airbag is extending and expanding and to regulate the movement of the airbag at the corner portion toward the interior side upon completion of the extension and expansion.
At the operating time of the head protecting airbag device thus constructed, the airbag folded on the upper edge of the side window positioned on the vehicle side face extends and expands downward to cover the side window.
This airbag protrudes downward from the upper edge side of the side window in the vicinity of the corner portion while being guided by the guide means. And, the airbag completes its extension and expansion while its movement to the interior side is regulated by the guide means.
At this time, the airbag is mounted at its front end on the pillar portion on the side of the side window toward the front. Moreover, the rear end is mounted at a position of the rear wall portion apart from the vehicle side face. And, the airbag is not loosened even it is bent to the interior side in the vicinity of the corner portion, because its movement to the interior side is regulated by the guide means.
As a result, the longitudinal tension can be developed in the airbag upon completion of the extension and expansion without any trouble between the front end and the rear end.
Even if the head protecting airbag device according to the invention is mounted on a vehicle such as a single-cab vehicle in which the rear wall portion is so arranged on the side of the side window toward the rear to be covered with the airbag so as to intersect the side window generally perpendicularly, therefore, the longitudinal tension can be easily developed in the airbag having completed the extension and expansion.
In the head protecting airbag device, moreover, it is preferable that the airbag includes at least one vertical expansion portion for expanding vertically by admitting an inflating gas when the airbag is extending and expanding.
With this construction of the head protecting airbag device, when the airbag is extending and expanding the vertical expansion portion can expand to shrink the airbag longitudinally by admitting the inflating gas. Therefore, a higher longitudinal tension can be developed in the airbag having completed its expansion.
In the head protecting airbag device thus constructed, moreover, it is preferable that upon completion of the expansion the vertical expansion portion in the vicinity of the guide means is arranged along the guide means, and that the airbag is so mounted on the rear wall portion as to extend generally linearly from and in the direction of the lower edge of the vertical expansion portion.
With the head protecting airbag device thus constructed, the vertical expansion portion exhibits a rigidity to some extent when it is charged with the inflating gas. Upon completion of the expansion of the airbag, moreover, the vertical expansion portion is pulled near its lower edge toward the rear of the vehicle. In other words, the vertical expansion portion turns its lower end pivoting on its upper end so that the higher longitudinal tension is developed at the lower edge side of the airbag.
Moreover, it is preferable that the portion of the airbag to be arranged facing the side of the guide means toward the exterior of the car when the airbag is extending and expanding is constructed of a non-inlet portion for admitting no inflating gas.
With the head protecting airbag device thus constructed, the guide means can be arranged very close to the exterior side to retain more space in the interior side.
In the head protecting airbag device thus constructed, moreover, it is preferable that the guide means is formed of a guide fixture made of a long metal member and includes a guide regulating portion extending vertically and a joint portion to be jointed to the car body, that the guide regulating portion can guide and regulate the movement of the airbag, and that the joint portion is arranged on either the upper or lower side of the guide regulating portion or both.
Moreover, the guide means may properly be formed of a band-shaped belt having flexibility and includes a guide regulating portion extending vertically and joint portions joining the guide to the car body so that the guide regulating portion can guide and regulate the movement of the airbag, and that the joint portions are arranged on the upper and lower ends of the guide regulating portion.
Moreover, the guide means may be mounted on a passenger seating seat arranged on the vehicle body.
In case the guide means is exemplified by a guide fixture made of a long metal member and including a guide regulating portion and a joint portion, a band-shaped belt having a flexibility or a passenger seating seat arranged in the vehicle body, it is easily possible to guide the portion of the airbag near the corner to regulate its movement toward the interior.
On the other hand, a second object of the invention can be achieved by a head protecting airbag device comprising:
an airbag folded and housed on the upper edge of a side window on the interior side of a vehicle; an inflator for feeding an inflating gas to the airbag; guide means mounted on the vehicle body; and engaging means arranged in the airbag for engaging with the guide means,
wherein the airbag extends and expands downward from the upper edge side of the side window, when the inflating gas flows in, to cover the interior side of the side window,
wherein the guide means is so vertically arranged as to guide the downward extension of the airbag,
wherein the guide-engaging portion can be guided by the guide means when the airbag is extending and expanding, and
wherein the airbag includes an initial vertical expansion portion arranged to expand along the guide means for moving the guide-engaging portion downward along the guide means at the beginning of the inflow of the inflating gas.
When the airbag in the head protecting airbag device thus constructed accepts the inflating gas from the inflator, the initial vertical expansion portion expands first of all. In accordance with the expansion of the initial vertical expansion portion, moreover, the guide-engaging portion moves downward while being guided by the guide means so that it is arranged at a predetermined expansion completion position of the airbag. Before the remaining portions of the airbag receive the inflating gas to develop the tension on the lower edge side of the airbag, the guide-engaging portion is guided in advance by the guide means to complete the extension of the airbag substantially. Therefore, the airbag can complete its extension and expansion without any trouble and also can develop longitudinal tension on the lower edge.
In the head protecting airbag device according to the invention, therefore, the airbag can be smoothly guided by the guide means to complete its extension, even if it is constructed to develop longitudinal tension on the lower edge upon completion of the extension and expansion.
In the head protecting airbag device thus constructed, it is preferable that the guide means is covered on its interior-facing side with an edge portion of the interior surface of the vehicle, which can open toward the interior side.
With the head protecting airbag device thus constructed, when the airbag does not extend, the guide means is covered on its interior side with the interior finish constructed of a pillar garnish or trim. Therefore, the decorative design of the vehicle having the guide means mounted thereon is improved. When the airbag is extending and expanding, the edge portion of the interior surface covering the interior-facing side of the guide means opens to the interior side so that it does not obstruct the extension and expansion of the airbag.
In the head protecting airbag device thus constructed, moreover, it is preferable that the guide means has a flexibility and is arranged to open and protrude the edge portion of the interior finish from the housed position of the guide means toward the interior side when the airbag is extending and expanding thereby to prevent the interference between airbag and the interior finish.
With the head protecting airbag device thus constructed, when the airbag is extending and expanding, the flexible guide means opens the edge portion of the interior finish and protrudes from the housed position toward the interior. Therefore, the airbag can extend and expand smoothly without its guide-engaging portion interfering with the interior finish.
In the head protecting airbag device thus constructed, still moreover, it is preferable that the airbag includes a plurality of vertical expansion portions for expanding vertically by admitting the inflating gas.
With the head protecting airbag device thus constructed, when the airbag is extending and expanding, each vertical expansion portion expands in such a way that the airbag shrinks longitudinally by admitting the inflating gas. After the airbag has completed its expansion, therefore, it is possible to develop a high longitudinal tension.
In the head protecting airbag device thus constructed, still moreover, it is preferable that the initial vertical expansion portion is arranged close to the inflator and upstream of the inflating gas.
With the head protecting airbag device thus constructed, when the airbag is extending and expanding, the inflating gas discharged from the inflator can be promptly introduced into the initial vertical expansion portion. In other words, this initial vertical expansion portion can expand earlier than the remaining portions of the airbag. As a result, the guide-engaging portion can promptly move downward while being guided by the guide member to extend the airbag promptly.